Electronic systems such as computers typically employ a mechanism to maintain the system sufficiently cool. A system that becomes too hot may malfunction. For example, a fan may be used to blow air over the system's electronics. Alternatively, or additionally, logic may “throttle” the system's processor. Throttling a processor causes the processor to operate at a slower speed which results in the processor producing less heat.
Turning on a fan helps cool the system, but produces acoustic noise that a user may find annoying. Throttling a processor also helps cool the system, but results in degraded performance which users typically do not prefer. Thus, a tradeoff is made between, on one hand, achieving the highest performance possible with the least amount of acoustic noise and, on the other hand, preventing the system from becoming so hot that the system no longer works properly.
Some portable systems, such as laptop computers, are used in contact with the user. For example, as the name indicates, a laptop computer may rest on a person's lap. Further, the user's hands may rest on a handrest near a touchpad while using the laptop computer's keyboard. It is possible that, while the cooling mechanism maintains the laptop computer sufficiently cool to avoid a malfunction, a human user, nevertheless, may find the laptop uncomfortable to the touch.